The call routing functionality in some operating systems, such as some ADTRAN VoiceCore™ applications as a non-limiting example, only considers the dialed number when making a call routing decision. In one example, a “switchboard” operates as a software component in a server or integrated communications platform and routes the call. This switchboard does not consider the source of the call when using its logic to route the call to a trunk. Internal and external calls can be made and survivability is a factor to connect some calls even though in one example the primary Voice over Internet Protocol (VoIP) service is reduced. Survivability is possible for some internal calls that are connected from one phone on the device as an integrated communications platform to another phone on the device without involving an external call-routing service. Survivability is possible for external calls if a secondary service is provided, e.g., when VoIP is the primary service and the secondary service is a PSTN connection. An emergency call takes priority over other calls, e.g., dialing 911. It is desirable to have more efficient routing based on the source of the call.